Pathology of the Urinary System II Flashcards
What causes Hypoxic/ Ischaemic injury?
Hypotension and/or ischaemia (heat stroke, dehydration)
* causes prolonged renal ischemia
* massive haemolysis- haemoglobinuric ATN
Necrosis of tubular epithelium and basement membrane
What is nephrotoxic injury?
- Nephrotoxins cause Direct damage to epithelial cells
- produces reactive metabolites in the tubular filtrates, which can cause renal tubular epithelial necrosis after reabsorption
- indirectly stimulate vasoconstriction of intertubular capillaries
- in absence of renal failure- reversible
What is AminoGlycoside toxiciy?
- Toxins are concentrated in lysosomes
- it escapes lysosomes to accumulate in the cytoplasm
- alters mitochondrial function and inhibits protein synthesis
- phospholipids accumulate intracellularly
What occurs when antifreeze/ oxalate nephrosis is absorbed?
- absorbed from the GIT
- A small percentage is oxidised by hepatic alcohol dehydrogenase to the toxic metabolites
- there is a direct interaction of the toxic metabolites on the tubular epithelium
- calcium-oxalate crystals precipitate in the tubular lumen, tubular epithelial cells and the interstitium
- tubular blockage -> degeneration and necrosis -> renal failure
What does oxalate nephrosis look like?
- large numbers of crystals in tubules
- usually arranged in rosettes or sheaves within the renal tubules
What is tubular ecstasia?
renal epithelial degeneration and necrosis with a preserved tubular basement membrane
What occurs when lilies are ingested?
- Vomiting and lethargy 1-5 days post ingestion
- The toxic ingredient is unknown
Occurs in cats
little amount = highly toxic
What occurs when grapes and raisins are ingested?
- Toxin is unknown
- Proximal tubular degeneration and necrosis
*
Name four toxins that cause haemoglobinaemia
- Chronic copper toxicity in sheep
- leptospirosis or babesiosis in cattle
- red maple toxicity in horses
- babesiosis or autoimmune haemolytic anaemia in dogs
What does haemoglinuric nephrosis look like grossly?
- renal cortex diffusely red-brown to blue-black
- Contains haemoglobin casts- red-black stippling of the capsular surface and continue into the cortex as radially orientated, dark red streaks
What is myoglobinuric nephrosis?
Acute and extensive muscle necrosis
* rhabdomylosis
* severe direct trauma to muscle
causes myoglobin release from the muscle
large concentrations of myoglobin in the glomerular filtrate can increase the tubular necrosis that occurs as a result of renal ischemia
What is leptospirosis?
- Interstitial nephritis
- causes abortion and stillbirths in livestock
- septicaemia, hepatitis, nephritis and meningitis
What does leptospirosis look like grossly?
- radiating pale streaks
- interstitial and subcapsular fibrosis
- jaundice
What does Encephalitozoon cuniculi look like?
- Occurs in rabbits
- obligate intracellular microsporidian parasite
- spreads through urine
- brain and kidney are the most heavily affected
- macrophages are unable to clear infection
What is ‘white-spotted kidney’?
- Common incidental lesion in young calves
- progresses to fibrosis when aged
Multifocal nonsuppurative interstitial
nephritis